CVE-2026-89951

HIGHPre-NVD 8.88.8—
EchelonGraph scoreHIGH confidence

Score 8.8 from GitHub Security Advisory (severity: HIGH) published 2026-09-16. A secondary CVSS source baseline 8.8; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: epss, ghsa, secondary
Trending — 3 sources updated this week
8.8EG
EchelonGraph verdictPlan mitigationSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 0.4%CVSS: 8.8Exploit: None knownExposed services: Not assessed

No fix is confirmed yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for the fix.

In the Linux kernel, the following vulnerability has been resolved:

batman-adv: fix stale receive device on merged fragments

Fragment reassembly reuses the skb from the highest-numbered buffered fragment as the merged packet. When that fragment was received on a hard interface which is deleted before the chain completes, the merged skb can re-enter the receive path with a stale skb->dev and skb_iif.

batadv_batman_skb_recv() passes such merged packets through the normal receive handlers again. DAT and bridge loop avoidance both derive the ARP header length from skb->dev, so they can dereference the freed net_device before the packet reaches the local mesh interface.

Refresh the receive device metadata from the current receive device before running the packet handlers. This keeps internally reinjected merged fragments consistent with the normal receive path after hard interface teardown.

CVSS v3
8.8
EG Score
8.8HIGHhigh confidence
EG Risk
44
EG Risk 44/100CISA SSVC

EG Risk is EchelonGraph's 0–100 priority score: it fuses intrinsic severity with real-world exploitation and automatability so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner. Distinct from the 0–10 EG Score (severity).

How it’s computed
Severity88% × 45%
Exploitation0% × 40%
Automatability30% × 15%
CISA SSVC: Track at low or medium mission impact; Track or Attend at high (mission-essential systems).
Action: No fix is confirmed yet. Restrict network exposure of the affected system or apply the vendor's mitigation within your standard update timelines at low or medium mission impact and sooner than that at high, and watch the vendor's advisory for the fix.
EPSS PROB
0.4%
EPSS %ILE
33rd
KEV
Not listed

CISA SSVCTrack at low or medium mission impact; Track or Attend at high (mission-essential systems).

No fix is confirmed yet. Restrict network exposure of the affected system or apply the vendor's mitigation within your standard update timelines at low or medium mission impact and sooner than that at high, and watch the vendor's advisory for the fix.

Exploitation none (no KEV listing, exploit record or EPSS ≥ 50%) · Automatable unknown (not published for this CVE) · Technical impact partial (CVSS below 9.0). Mission impact is CISA's Mission & Well-being decision point, and only you can judge it: high means the affected system is essential to your organisation's mission, or its compromise could cause irreversible harm to people. CISA's decision table

Published

September 16, 2026

Last Modified

September 16, 2026

Advisory Details (8)

Auto-updated Sep 16, 2026
No patch confirmed yet.
generic

batman-adv: fix stale receive device on merged fragments - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/ad46c907d7d9975a285c1e89a4adde652eaa93f5
generic

batman-adv: fix stale receive device on merged fragments - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/2dffc8c44b6e3347b3719c6419c07b4a18fea895
generic

batman-adv: fix stale receive device on merged fragments - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/e91d2cc7441d89a45bad73ad9789159c7441cb80
generic

batman-adv: fix stale receive device on merged fragments - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/a2c272da99c2077088083c14961cf2f1e4506995
generic

batman-adv: fix stale receive device on merged fragments - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/6df64825f8b199921120c685af2abca14b077331
generic

batman-adv: fix stale receive device on merged fragments - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/f4b4ae763b5d59319fad62a00c76676758e7dafa
generic

batman-adv: fix stale receive device on merged fragments - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/f830c2dfc1431764db9256b3d5db1695fc9a7f56
generic

batman-adv: fix stale receive device on merged fragments - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/63d86250fa7cbe22451369bd1c0881dfc8190958

Vendor Advisories for CVE-2026-89951(1)

These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.

Affected Packages

(4 across 3 ecosystems)
Debian:12(2)
PackageVulnerable rangeFix by version rangeDependents
linux6.1.106-1 ... 7.2~rc7-1~exp1 (360 versions)
  • every version on: no fix on record
—
linux-6.126.12.100-1~deb12u1, 6.12.101-1~deb12u1, 6.12.107-1~deb12u1
  • every version up to 6.12.111-1~deb12u1: fixed in 6.12.111-1~deb12u1
—
Debian:13(1)
PackageVulnerable rangeFix by version rangeDependents
linux6.12.100-1 ... 6.12.96-1 (35 versions)
  • every version up to 6.12.111-1: fixed in 6.12.111-1
—
Debian:14(1)
PackageVulnerable rangeFix by version rangeDependents
linux6.12.100-1 ... 7.2~rc7-1~exp1 (179 versions)
  • every version up to 7.2.6-1: fixed in 7.2.6-1
—

Data Freshness Timeline

(refreshed 30× in last 7d / 84× in last 30d)

Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.

  1. 2026-10-05 00:48 UTCEG score recompute
  2. 2026-10-05 00:47 UTCGHSA enrichment
  3. 2026-10-04 23:22 UTCEPSS rescore
  4. 2026-10-04 13:26 UTCGHSA enrichment
  5. 2026-10-04 02:07 UTCGHSA enrichment
  6. 2026-10-03 14:49 UTCEG score recompute
  7. 2026-10-03 14:49 UTCGHSA enrichment
  8. 2026-10-03 03:31 UTCEG score recompute
  9. 2026-10-03 03:31 UTCGHSA enrichment
  10. 2026-10-02 16:13 UTCGHSA enrichment
  11. 2026-10-02 16:13 UTCGHSA enrichment
  12. 2026-10-02 16:12 UTCGHSA enrichment
  13. 2026-10-02 16:12 UTCGHSA enrichment
  14. 2026-10-02 16:12 UTCGHSA enrichment
  15. 2026-10-02 04:52 UTCEG score recompute
  16. 2026-10-02 04:52 UTCGHSA enrichment
  17. 2026-10-01 19:51 UTCEPSS rescore
  18. 2026-10-01 17:30 UTCGHSA enrichment
  19. 2026-10-01 06:12 UTCGHSA enrichment
  20. 2026-09-30 18:54 UTCEG score recompute
  21. 2026-09-30 18:54 UTCGHSA enrichment
  22. 2026-09-30 15:04 UTCEPSS rescore
  23. 2026-09-30 07:36 UTCGHSA enrichment
  24. 2026-09-29 20:18 UTCEG score recompute
  25. 2026-09-29 20:18 UTCGHSA enrichment
Show 59 more
  1. 2026-09-29 08:59 UTCGHSA enrichment
  2. 2026-09-28 21:40 UTCEG score recompute
  3. 2026-09-28 21:40 UTCGHSA enrichment
  4. 2026-09-28 13:52 UTCEPSS rescore
  5. 2026-09-28 13:52 UTCEPSS rescore
  6. 2026-09-28 10:22 UTCGHSA enrichment
  7. 2026-09-27 23:04 UTCEG score recompute
  8. 2026-09-27 23:04 UTCGHSA enrichment
  9. 2026-09-27 13:49 UTCEPSS rescore
  10. 2026-09-27 11:45 UTCGHSA enrichment
  11. 2026-09-27 00:27 UTCEG score recompute
  12. 2026-09-27 00:27 UTCGHSA enrichment
  13. 2026-09-26 15:59 UTCEPSS rescore
  14. 2026-09-26 13:09 UTCGHSA enrichment
  15. 2026-09-26 01:48 UTCEG score recompute
  16. 2026-09-26 01:48 UTCGHSA enrichment
  17. 2026-09-25 14:28 UTCGHSA enrichment
  18. 2026-09-25 03:02 UTCGHSA enrichment
  19. 2026-09-24 15:41 UTCEG score recompute
  20. 2026-09-24 15:41 UTCGHSA enrichment
  21. 2026-09-24 14:04 UTCEPSS rescore
  22. 2026-09-24 04:23 UTCEG score recompute
  23. 2026-09-24 04:23 UTCGHSA enrichment
  24. 2026-09-23 17:54 UTCEPSS rescore
  25. 2026-09-23 17:04 UTCGHSA enrichment
  26. 2026-09-23 05:45 UTCGHSA enrichment
  27. 2026-09-22 18:27 UTCEG score recompute
  28. 2026-09-22 18:27 UTCGHSA enrichment
  29. 2026-09-22 16:01 UTCEPSS rescore
  30. 2026-09-22 07:08 UTCEG score recompute
  31. 2026-09-22 07:08 UTCGHSA enrichment
  32. 2026-09-21 21:09 UTCEPSS rescore
  33. 2026-09-21 19:50 UTCGHSA enrichment
  34. 2026-09-21 08:31 UTCGHSA enrichment
  35. 2026-09-20 21:11 UTCEG score recompute
  36. 2026-09-20 21:11 UTCGHSA enrichment
  37. 2026-09-20 20:16 UTCEPSS rescore
  38. 2026-09-20 09:53 UTCGHSA enrichment
  39. 2026-09-19 22:34 UTCEG score recompute
  40. 2026-09-19 22:34 UTCGHSA enrichment
  41. 2026-09-19 11:16 UTCGHSA enrichment
  42. 2026-09-18 23:58 UTCEG score recompute
  43. 2026-09-18 23:58 UTCGHSA enrichment
  44. 2026-09-18 19:28 UTCEPSS rescore
  45. 2026-09-18 12:40 UTCGHSA enrichment
  46. 2026-09-18 01:22 UTCEG score recompute
  47. 2026-09-18 01:22 UTCGHSA enrichment
  48. 2026-09-17 19:32 UTCEPSS rescore
  49. 2026-09-17 14:04 UTCGHSA enrichment
  50. 2026-09-17 02:46 UTCEG score recompute
  51. 2026-09-17 02:45 UTCGHSA enrichment
  52. 2026-09-16 15:23 UTCEG score recompute
  53. 2026-09-16 15:23 UTCGHSA enrichment
  54. 2026-09-16 14:47 UTCEG score recompute▲ 8.80
  55. 2026-09-16 14:47 UTCGHSA enrichment
  56. 2026-09-16 14:45 UTCMITRE cvelistV5CVSS v3 → 8.8 · severity → HIGH
  57. 2026-09-16 11:21 UTCNVD update
  58. 2026-09-16 10:38 UTCEG score recompute
  59. 2026-09-16 10:36 UTCMITRE cvelistV5first tracked

Frequently asked(5)

What is CVE-2026-89951?
CVE-2026-89951 is a high vulnerability published on September 16, 2026. In the Linux kernel, the following vulnerability has been resolved: batman-adv: fix stale receive device on merged fragments Fragment reassembly reuses the skb from the highest-numbered buffered fragment as the merged packet. When that fragment was received on a hard interface which is deleted…
When was CVE-2026-89951 disclosed?
CVE-2026-89951 was first published on September 16, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-89951 actively exploited?
CVE-2026-89951 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0.4% probability of exploitation in the next 30 days (33rd percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2026-89951?
CVE-2026-89951 has a CVSS base score of 8.8 (a secondary CVSS source that NVD displays; NVD's own analysis pending).
How do I remediate CVE-2026-89951?
No fix for CVE-2026-89951 is confirmed yet. Until one is published, restrict network exposure of the affected system or apply the vendor's mitigation — for example, keep it off the internet or limit it to trusted networks — and watch the vendor's advisory for the fix. The vendor advisories EchelonGraph has for CVE-2026-89951 are linked in the Vendor Advisories panel on this page.

Dependency Blast Radius

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